Gas lift valve



C. R. CANALIZO GAS LIFT VALVE April 28, 1964 2 Sheets-Sheet 1 Filed June 25, 1960 gli ztl INVENTOR Carlos R. Conolizo ATTORNEY April 1964 c. R. CANALIZO 3,130,743

GAS LIFT VALVE Filed June 23, 1960 2 Sheets-Sheet 2 ma g 1 id r. F

Fig. 4

INVENTOR G- Carlos R. Conolizo ATTORNEY United States Patent Ofiice 3,130,743 Patented Apr. 28, 1964 3,139,743 GAE LET VALVE Carlos R. Canalizo, Dailas, Tex., assignor to Otis Eng:-

neering Corporation, Dailas, Tex., a corporation of Delaware Fiied dune 23, 196i), Ser. No. 38,342 7 Claims. (ill. 137-155) This invention relates to well tools and more particularly to well tools for removing fluids from the bores of wells by gas pressure.

An object of the invention is to provide a new and improved well tool for removing the liquids produced by wells through an inner well tubing disposed in a casing of the well wherein gas from the annular flow passage between the well casing and the inner well tubing provides the power for transporting the liquids to the surface through the inner well tubing.

Another object is to provide a Well tool for automatically removing liquid from the bore of a well which includes a valve which opens intermittently to permit flow of the gas from the annular flow passage between the well casing and an inner well tubing into the well tubing to transport liquids present in the well tubing above the valve to the surface.

Still another object is to provide a well tool for use in wells having a casing and an inner well tubing telescoped therein which includes a valve providing communication between the interior of the well tubing and the annular space between the casing and the well tubing and which is responsive only to the pressure within the tubing above the valve to permit flow of fluid from the annular space into the tubing when the pressure within the tubing exceeds a predetermined value.

A further object is to provide a Well tool for use in wells having a casing and an inner tubing telescoped therein which includes a valve affording communication between the interior of the tubing and the annular space between the casing and the inner tubing which opens to permit flow of fluid from the well easing into the inner tubing when the pressure within the tubing rises above a predetermined value without regard to the value of the pressure in the annular space between the well casing and the inner tubing and which closes when the pressure within the tubing decreases to substantially the same predetermined value at which the valve opens.

A further object is to provide a well tool for use in wells having a casing and an inner tubing telescoped therein which includes a valve affording communication between the interior of the tubing and the annular space between the casing and the inner tubing which opens to permit flow of fluid from the well easing into the inner tubing when the pressure within the tubing rises above a predetermined value, the valve being biased to closed position by a resilient means and being disposed in a housing having a lateral port which permits flow of fluid from the exterior of the housing into the inner tubing through the housing when the valve is in open position, the pressure of the fluid entering through the lateral port having no tendency to move the valve to open position from closed position when the valve is in closed position and being effective to: hold the valve in open position after it has been moved to open position until the pressure within the tubing drops to the predetermined value at which the valve opens.

A still further object is to provide a well tool for use in wells having a casing and an inner tubing telescoped therein which includes a valve afiording communication between the tubing and the casing which opens to permit flow of fluid from the well easing into the inner tubing when the pressure within the tubing arises above a predetermined value, the pressure of the fluid in the well casing being ineffective to move the valve to open position until the pressure within the tubing moves the valve toward open position whereupon the pressure within the Well casing is effective to move the valve to fully open position and hold it against movement to closed position until the pressure within the tubing decreases to substantially the predetermined value at which the valve opened.

Another object is to provide a fluid actuated valve having a housing provided with a longitudinal flow passage and a lateral port opening to the exterior of the housing and communicating with the longitudinal flow passage and having a member movable toward a closed position preventing flow of fluid between the lateral port and the longitudinal flow passage, the valve having resilient means responsive to the pressure of the fluid from the exterior of the valve housing when the movable member moves toward open position for moving the movable member toward a fully open position.

Still another object is to provide a fluid actuated valve having a housing provided with a longitudinal flow passage and a lateral port opening to the exterior of the housing and communicating with the longitudinal flow passage and having a movable member movable toward a closed position preventing flow of fluid between the lateral port and the longitudinal flow passage, the valve having resilient means responsive to the pressure of the fluid from the exterior of the valve housing when the movable members move toward open position for moving the movable member toward a fully open position and a biasing means for biasing the movable member toward a closed position.

Still another object of the invention is to provide a new and improved gas lift valve for automatically removing liquid from the bore of a well which opens intermittently to permit flow of gas introduced into the annular flow passage between the well casing and an inner well tubing into the well tubing to transport liquids present in the well tubing above the valve to the surface.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURE 1 is a vertical partly sectional view of a well tool embodying the invention for removing fluids from a well showing the valve in closed position.

FIGURE 2 is a vertical sectional view of the well tool, similar to FIGURE 1, showing the valve thereof in open position;

FIGURE 3 is a diagrammatic illustration of the well tool of FIGURE 1 positioned in a tubing of a well; and

FIGURE 4 is a view similar to FIGURE 3 showing the well tool of FIGURE 1 connected to a tubing extension of a well tubing of a well.

Referring now particularly to FIGURES 1 and 2 of the drawing, the well tool 10 for automatically and intermittently removing liquids accumulated in the bottom of a well by the pressure in the well includes a housing 11 having an upper valve seat section 12 provided with a reduced threaded end 13 by means of which the well tool may be connected to another well tool, such as a tubing extension or ananchoring and sealing device. The valve housing also includes a seal section 14 having a reduced upper end portion threaded into the lower end of the valve seat section 12, a bellows section 15 threaded into the lower end of the seal section, a spring section 16 threaded on the lower end of the bellows section and a plug 17 threaded into the lower end of the spring section. A gasket 18 is interposed between an upwardly facing annular shoulder of the plug and the lower end of the spring housing to seal therebetween. The plug may also be provided with an external annular recess in which is disposed an O-ring 19 or other suitable sealing means for further sealing between the spring section and the valve plug.

A valve 22 is mounted in the housing 11 for limited longitudinal movement between the closed position illustrated in FIGURE 1 wherein the hardened seat insert 23 on the upper end of the valve stem 24 engages the ring valve seat 25 disposed in the seat section 12 and a lower open position illustrated in FIGURE 2 wherein the downwardly facing stop shoulder 23 formed by the enlarged annular flange 29 of the valve engages an upwardly facing internal annular shoulder 39 of the bellows housing. The valve seat 25 may be press fitted in the intermediate enlarged section of the bore or flow passage 32 of the seat section 12 which provides a downwardly facing shoulder 33 which limits upward movement of the seat 25.

The seat section of the housing 11 has a threaded lateral aperture or port 35 in which is threaded a bean 36 having a relatively large orifice $8 affording communication between the fiow passage of the seating section below the seat 25 and the exterior of the housing. it will be apparent that when the valve 22 is in the lower position illustrated in FIGURE 2, fluid may flow from the exterior of the housing through the orifice 33 into the longitudinal flow passage 32 of the seat section and thence upwardly.

The sealing section 14 has an internal annular recess in which is disposed a sealing means such as a gasket or ring 45 which seals between valve stem 24 of the valve 22 and the housing. The external diameter of the valve stem at the point of contact with the seal means 49 is equal to the diameter of the circular exterior line of contact of the valve with seat insert 23 so that the cross-sectional areas of the valve 22 exposed to the pressure of the fluid from the exterior of the housing, when the valve is in its upper closed position, cause the forces exerted by such fluid pressure on the valve to counterbalance and will not tend to move the valve to open or to closed position. The seal section of the housing also has internal annular recesses above and below the seal means 40 in which are disposed felt wipers 41 which wipe or clean the external surface of the valve stem as the valve moves between its open and closed positions and prevent access of dirt to the seal means and thus prolong the life of the seal means.

The valve 22 is provided with a longitudinal flow passage 43 which at its upper end opens through the annular hardened seat insert 23 to the flow passage 32 of the housing 11 and whose lower end opens through a lateral passage 44 into the internal annular recess 45 of the sealing section of the housing. A lateral port or aperture 46 of the sealing section opens into the internal annular recess 45 thereof. A bean 48 is threaded in this lateral aperture and has a resrticted orifice 49 of smaller effective cross-sectional area than the relatively large orifice 38 of the bean 36 of the seat section 12 of the housing.

A strainer sleeve 52 is disposed about the housing 11 and has a retainer means, such as a set screw 54, which extends through a threaded bore in the lower end of the strainer sleeve 52 into a suitable external recess 55 of the bellows section to rigidly secure the strainer sleeve on the housing. The sleeve is provided with a pair of longitudinally spaced internal recesses in which are disposed O-rings 56 or other suitable sealing means which seal between the seat section of the housing and the strainer sleeve above the orifice 49 and which seal between the sealing section of the housing and the strainer sleeve below the orifice 49.

The sleeve has an internal annular recess 60 aligned with the orifice 49 and communicating therewith and also has a plurality of lateral ports 62 which communicate with the internal recess 60 whereby fluid from exteriorly of the housing may flow through the lateral ports of the sleeve into the internal recess 60, thence through the orifice 49 of the bean 4-8 and lateral aperture 46 of the seal section into the internal recess 45, thence through the lateral passage 44 of the valve into the flow passage 43 thereof and thence to the flow passage 32 of the seat section of the housing. The strainer sleeve also has an external annular recess 65 in which is disposed the screen 66 extending about the strainer sleeve for straining debris from the fluids flowing into the valve housing.

The bellows section 15 has secured to its lower end a lower annular external flange 70 of a bellows 71 whose vertical flange 72 at the upper end thereof is telescoped over and secured to the annular shoulder 74 of the valve stem positioned below the external flange 29. The lower and upper flanges are secured to the bellows section 15 of the housing and to the valve stem by welding or soldering to insure a gas-tight seal therebetween. The bellows is disposed about the valve stem and is spaced inwardly of the internal cylindrical surface of the bellows section so that the bore 75 of the bellows section outwardly of the bellows opens upwardly to communicate with the internal annular recess 45 of the seal section and therefore with the flow passages 43 and 44 of the valve stem 24. Bellows section 15 is provided with external annular recesses above and below its recess 55, in which are disposed seal means, such as O-rings 77, which seal between the bellows section and the seal and spring sections of the housing. The pressure within the longitudinal flow passage 43 of the valve stem 24 exerts a force on the bellows 71 which tends to move the valve downwardly from the closed position illustrated in FIGURE 1 towards the open position illustrated in FIGURE 2. The valve stem 24 is provided at its lower end with an annular ring guide telescoped on the reduced lower end portion 81 of the valve stem. The ring guide is somewhat smaller in diameter than the internal diameter of the tubular spring section 16 of the housing 11 so that it permits upward and downward movement of the valve but tends to prevent any lateral movement thereof when such movement exceeds predetermined limits by engaging the internal surface of the spring section. The valve 22 is biased upwardly towards the closed position by a helical spring 83 disposed in the spring section whose upper end bears against the ring guide Sit and whose lower end bears against an adjusting screw $5 threaded in the spring housing. The adjusting screw is locked against movement from any adjusted position by a suitable detent means which may comprise a nylon pellet 87 disposed in an external recess of the screw which frictionally engages the internal threads of the housing to prevent undesired rotation of the screw in the housing. The adjusting screw is provided with an aperture 8% to provide for equalization of pressure above and below the adjusting screw upon longitudinal movement of the valve since the bellows 71, the spring housing and the plug form a closed chamber 289 having no vent so that the chamber, if de sired, may be charged with a compressible gas to any desired pressure either greater or lesser than atmospheric pressure. If desired, a fitting 90 may be provided through which gas may be introduced into the chamber 39.

In use, the well tool 11) may be positioned in the lower portion of an inner tubing 1431 of a well having a casing 102 by means of an anchoring and sealing device 103 of any suitable type, such as the Type W Otis mandrel assembly illustrated on page 3971 of the Composite Catalog of Oil Field Equipment and Services, 1959 edition. The well tool 10 is connected to the anchoring and sealing device by means of any suitable coupling which connects the threaded end portion 13 of the seat section of the housing 11 to the locator mandrel of the locking assembly.

The well casing is provided at the surface with an outlet pipe 1134 through which the gas produced from a producing formation 105 is conducted to a reservoir or point of use. The tubing is similarly provided with an outlet pipe 108 through which fluids forced to the surface through the inlet tubing 101 are conducted to an open tank or to a gas-liquid separator. The well of course has the usual wellhead 110.

The well casing has perforations 112 through which the fluids produced from the production formation 105 enter into the well and has a cement or other plug 113 which closes the lower end of the Well casing. The fluids entering into the casing through the perforations 112 may consist of a mixture of gas and liquids, such as oil. Such liquids tend to accumulate in the lower end of the well casing and if they are not removed but are permitted to accumulate in the well casing, hinder production of gas.

The gas in the annulus or annular space 115 between the casing and the tubing is maintained at a higher pressure than the pressure existing in the tubing above the well tool 10. The produced liquids from the formation 105 flow through the apertures 62 of the strainer sleeve of the well tool 10, the internal annular recess 64) of the strainer sleeve, the orifice 49 of the bean 48, the aperture 46 of the seal section, the internal recess 45 of the seal section, the lateral passage 44 and the longitudinal flow passage 43 of the valve stem of the valve 22, the longitudinal flow passage 32 of the seat section of the valve housing and thence through the anchoring and sealing device into the inner tubing 1831. Since the orifice 49 is relatively small in cross-sectional area, the pressure within the annular recess 45 of the seal section of the housing, when no liquid is present in the inner well tubing above the well tool, is substantially less than the pressure in the annulus 115 of the well. The pressure of the fluid from within the well casing is therefore inefifective to act on the bellows 71 to move the valve downwardly to open position. As the liquids accumulate, their level rises in the well casing and in the lower end of the well inner tubing until it is disposed above the orifice 49 of the bean 48. The well liquids are then forced, due to the pressure differential between the interior of the tubing above the well tool and the casing through the orifice 49, the lateral flow passage 44 and the longitudinal flow passage 43 of the valve 22, the flow passage 32 of the seat section of the valve housing and the anchoring and sealing device in the well tubing. The pressure of the column of liquid acting on the bellows, since the chamber 75 is in communication with the annular recess 45, increases until it reaches a predetermined value which exerts a force on the bellows sufliciently great to overcome the force of the spring 83 which is biasing the valve to its upper closed position. The fluid pressure in the well casing also acts through the large orifice 38 on the upper portion of the valve stem but since the force exerted by the pressure acting through the orifice 33 on the valve is counterbalanced due to the substantially equal cross-sectional areas across the area of contact of the valve within the valve seat and of the seal ring with the valve stem, the fluid pressure from within the well casing does not tend to move the valve toward open position or toward closed position.

When the column of liquids present in the well tubing above the well tool reaches a certain height, its hydrostatic pressure causes a downward force of predetermined value to be exerted on the bellows 71. The valve is then moved downwardly by the bellows towards its open position. As soon as the valve moves out of contact with the valve seat 25, the fluid pressure exerted by the fluid entering through the large orifice 38, which is greater than the pressure within the tubing above the well tool, is immediately communicated to the bellows 71 and exerts a force thereon to cause the valve to move to its fully open position. The pressure of the fluids in the annulus 115, once the valve has been moved to its open position, forces the fluids in the lower end of the well casing 102 to flow inwardly into the housing 11 of the well tool, primarily through the orifice 38 and of course to some extent through the orifice 49, into the valve housing and thence, in the case of the fluids entering through the orifice 38 through the ring valve seat and through the flow passaves sage 32, and in the case of the fluids entering through the orifice 49 through the internal recess 45 of the seal section, through the flow passages 44 and 43 of the valve stem and through the valve seat to the flow passage 32 and thence upwardly through the anchoring and sealing device to the well tubing 161.

Since the liquids accumulate in the well casing as well as in the tubing, the column of liquids in the annulus will be depressed by the pressure of the fluids of the well as the liquids are forced upwardly in the tubing. When the level of liquids present in the well casing is depressed below the lower end of the inner tubing 101, the gas will flow up through the lower end of the well tubing to the orifices 3% and 49 and thence through the well tool 1% to the well inner tubing below the column or slug of well liquids. The gas will then accelerate the movement of the well liquids upwardly through the well tubing and lift or force this column of well liquids to the surface pipe 108 where it is expelled from the surface pipe. As the column or slug of liquid above the gas in the tubing is expelled the pressure within the tubing above the well tool decreases. As a result, the remainder of the slug of well liquids is further accelerated by the expansion of the gas below t e slug and causes an accelerated decrease in the pressure. At some time before the slug of well liquid is completely expelled from the pipe 108, the pressure drop across the orifice 38 and 49 becomes so great that the pressure within the passage 32 of the seat section, and therefore within the chamber 75 of the bellows housing, decreases substantially to the same predetermined value that existed therein at the time the bellows opened the valve. The force of the spring 83 is then effective to move the valve back to closed position. The remaining portions of the slug or column of well liquids are then completely expelled from the pipe M8 by the continued expansion of the gas within the tubing 101 and the gas then escapes to the atmosphere further decreasing the pressure within the well tubing. The well tool 19 is now back in its initial condition and the accumulation of liquids at the bottom of the well casing 102 now continues to increase until the liquids are again forced into the well tubing through the well tool 10 and the same cycle of operation of the well tool is repeated resulting in the expellation of another slug or column of liquid from the well. This cycle of operation is repeated automatically and prevents the accumulation of well fluids in the casing.

The size of orifice 49 is so selected that it is small enough to prevent undue waste of gas produced from the formation 105 when the valve 22 is in closed position but 18 large enough to pass the entire amount of liquid pro duced from the formation 105 and at the same time is sutficiently large to permit the liquids to rise in the inner tubing without rising in the annulus to a height hindering production of well fluids. Orifice 38 is so chosen that it is large enough to permit gas to flow therethrough to lift the slug or column of liquid efficiently but is small enough to permit the valve to close before the liquid slug has been completely expelled from the well.

It will be noted that the valve moves between its open and closed positions solely in response to the pressure conditions within the inner tubing, the pressure in the well casing having no effect upon such movement since the only communication between the interior of the well tubing and the well casing, when the valve 22 is in closed position, is through the restricted orifice 49 and since the pressure within the well tubing is always smaller than the pressure within the well casing annulus 115. The pressure within the annulus acting through the orifice 38 is completely ineffective to act upon the valve when the valve is in closed position since the force it exerts on the valve tending to open it is counterbalanced by the equal force that it exerts on the valve tending to move it to closed position due to the equal cross-section areas across the valve seat and across its valve stem at the location of the seal ring 4%. When the valve is in open position, the orifice 3%, while admitting flow of fluid from the annulus into the well tubing, nevertheless maintains a pressure d'u'ferential due to its restricted orifice so that movement of the valve from open position to closed position is again due only to the pressure conditions within the well tubing.

It will further be noted that the valve 22 is moved from its closed position to its open position by the force of fluid pressure exerted on the bellows 71 when a liquid slug or column of predetermined height exerting a pressure of predetermined value on the bellows accumulates in the Well inner tubing by flow through the orifice 49 of the bean i8, and that it closes again when the pressure again falls to substantially the same predetermined value or to a value which is slightly lower than the opening. The difference in opening and closing values of pressure is needed to overcome the friction of the seal ring 49 and the wipers 41.

It will further be seen that the adjustment of the valve by means of the adjusting screw causes it to open at a preselected pressure condition within the inner tubing which is not affected by the pressure at the bottom of the well within the casing so that the valve will open when a predetermined pressure condition occurs within the inner tubing of the well tool It) as determined solely by the predetermined height of the column or slug of liquid allowed to accumulate and rise in the inner tubing.

in FIGURE 4 the well tool id is shown connected to the bottom end of a tubing extension 120 whose upper end is releasably connected in the lower end or" the well tubing 101 by an anchoring and sealing device 1133 of the same type as described in connection with the well illustrated in FIGURE 3.

It will be noted that the well casing extends through producing formations 121, 122 and 12.3 as well as the producing formation 105 with only the lowermost producing formation 105 having fluid communication with the interior of the well casing through the perforations 112 therein. In a well having a plurality of spaced producing formations, the inner tubing ltll is generally positioned with its lower end sli htly above or at the level of the uppermost producible zone so that different producing zones may be selectively placed into production by cementing or otherwise closing off the perforations to a formation which it is no longer desired to produce and perforating the casing at the level of the next formation from which it is desired to produce liquids. in these installations, it is therefore desirable that the well tubing not extend through the upper production zones so that in further operations of the well it is not necessary to perforate or remove the well tubing.

It will be noted that the well tool It is lowered to the level of the producing formation so that it will function in the same manner as described above intermittently and automatically to remove the liquids from the bottom of the well and not permit an accumulation of liquids to rise in the well casing which would hinder or render less effective the production of well liquids from the producing formations.

It will thus be noted that the well tool it) may be used in wells producing both gases and liquids to cause the produced gases present in the well casing to transport the excess liquids produced by the well from the bottom of the well to the surface through an inner well tubing.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool for admitting fluids into the interior of a tubing including: a housing connectable to the tubing and having a flow passage opening into the interior of a tubing when the well tool is connected thereto, said housing having a lateral aperture communicating said flow passage with the exterior of the housing and of a tubing when the housing is connected thereto; valve means mounted in said housing and movable between an open position wherein said valve means permits fluids to flow through said aperture and thence into said passage and a closed position wherein said valve closes said flow passage preventing flow of fluids from said aperture and through said flow passage; means operatively associated with said valve means and said housing and responsive to fluid pres sure in said flow passage for moving said valve means from closed position to open position when said fluid pressure increases to a predetermined value; and biasing means for moving said valve means from open position to closed position when the fluid pressure in said flow passage decreases to substantially said predetermined value, said honing having a second lateral aperture of smaller orifice than said first mentioned aperture, said second lateral aperture communicating said flow passage with the exterior of the housing and of a tubing when the housing is connected thereto, said second lateral aperture being in communication at all times with and permitting flow of fluid at all times from the exterior of the housing into said flow passage.

2. A well tool for admitting fluids into the interior of a tubing including: a housing connectable to a tubing and having a flow passage opening into the interior of a tubing when the well tool is connected thereto, said housing having a lateral aperture communicating said flow passage with the exterior of the housing and of a tubing when the housing is connected thereto; valve means mounted in said housing and movable between an open position wherein said valve means permits fluids to flow through said aperture into said passage and a closed position wherein said valve means closes said flow passage to prevent flow of fluid from said aperture and through said flow passage; means operatively associated with said valve means and said housing and responsive to fluid pressure in said flow passage for moving said valve means from closed position to open position when said fluid pressure increases to a predetermined value; and biasing means for moving said valve means from open position to closed position when the fluid pressure in said flow passage decreases to substantially said predetermined value, said valve mean having equal opposed cross-sectional areas exposed to the pressure of the fluid entering through said aperture when said valve means is in closed position whereby forces exerted by said pressure on said valve means are counterbalanced and do not tend to move said valve means toward open or closed position when said valve means is in said closed position, said housing having a second lateral aperture of smaller orifice than said first mentioned aperture communicating said flow passage with the exterior of the housing and of a tubing when the housing is connected thereto, said second lateral aperture being in communication at all times with said flow passage.

3. A well tool including: a housing having a flow passage and a lateral aperture intermediate the ends of said housing communicating said flow passage with the exterior of the housing; a valve means comprising an elongate body longitudinally slidable in said housing, said housing having a valve seat engageable by said elongate body when said elongate body is moved in one direction to one extreme longitudinal position; fluid pressure responsive means operatively associated with said elongate body for moving said elongate body from said one extreme po sition to an open position permitting fluid to flow between said aperture and said flow passage; and sealing means between said elongate body and said housing, said lateral aperture being disposed between said valve seat and Sa sealing means, said elongate body closing said flow passage to prevent flow of fluids from said aperture to said flow passage when said elongate body is in said one extreme longitudinal position, said elongate member having a fiow passage communicating with said flow passage of the housing and extending past said sealing means to expose said fluid pressure responsive means at all times to fluid pressure from said flow passage of said housing, said housing having a second aperture communicating the exterior of the housing at all times with and permitting flow of fluids at all times from the exterior of the housing into said flow passage of said elongate member, said second aperture having a smaller orifice than said first aperture.

4. A well tool including: a housing having a flow passage and a lateral aperture intermediate the ends of said housing communicating said flow passage with the exterior of the housing; a valve means comprising an elongate body longitudinally slidable in said housing, said housing having a valve seat engageable by said elongate body when said elongate body is moved in one direction to one extreme longitudinal position in said housing; fluid pressure responsive means operatively associated with said elongate body for moving said elongate body from said one extreme position to an open position permitting fluid to flow between said aperture and said flow passage; and sealing means between said elongate body and said housing, said lateral aperture being disposed between said valve seat and said sealing means, said elongate body closing said flow passage to prevent flow of fluids from said aperture to said flow passage when said elongate body is in said one extreme longitudinal position, said elongate member having a flow passage communicating wtih said flow passage of the housing and extending past said sealing means to expose said fluid pressure responsive means at all times to fluid pressure from said flow passage of said housing; and means biasing said elongate member toward said valve seat, said housing having a second aperture communicating the exterior of said housing at all times with and permitting flow of fluids at all times from the exterior of the housing into said flow passage of said elongate member, said second aperture having a smaller orifice than said first aperture.

5. A well tool including: a housing having a flow passage and a lateral aperture intermediate the ends of said housing communicating said flow passage with the exterior of the housing; a valve means comprising an elongate body longitudinally slidable in said housing, said housing having a valve seat engageable by said elongate body when said elongate body is moved in one direction to one extreme longitudinal position; fluid pressure responsive means operatively associated with said elongate body for moving said elongate body from said one extreme position to an open position permitting fluid to flow between said aperture and said flow passage; and sealing means between said elongate body and said housing, said lateral aperture being disposed between said valve seat and said sealing means, said elongate body closing said flow passage to prevent flow of fluids from said aperture to said flow passage when said elongate body is in said one extreme longitudinal position, said elongate member having a flow passage communicating with said flow passage of the housing and extending past said sealing means to expose said fluid pressure responsive means at all times to fluid pressure from said flow passage of said housing, said housing having a second lateral aperture communicating the exterior of said housing at all times with and permitting flow of fluids at all times from the exterior of the housing into said passage of said elongate member, said second aperture having a smaller orifice than said first aperture, said fluid pressure responsive means comprising a bellows having one end connected to said elongate member and another end connected to said housing to form a chamber between said housing and said bellows, said passage of said elongate member in said second lateral aperture opening into said closed space.

6. A well tool including: a housing having a flow passage and a lateral aperture intermediate the ends of said housing communicating said flow passage with the eX- terior of the housing; a valve means comprising an elongate body longitudinally slidable in said housing, said housing having a valve seat engageable by said elongate body when said elongate body is moved in one direction to one extreme longitudinal position in said housing; fluid pressure responsive means operatively associated with said elongate body for moving said elongate body from said one extreme position to an open position permitting fluid to flow between said aperture and said flow passage; and sealing means between said elongate body and said housing, said lateral aperture being disposed between said valve seat and said sealing means, said elongate body closing said flow passage to prevent flow of fluids from said aperture to said flow passage when said elongate body is in said one extreme longitudinal position, said elongate member having a flow pasage communicating with said flow passage of the housing and extending past said sealing means to expose said fluid pressure responsive means at all times to fluid pressure from said flow passage of said housing; and means biasing said elongate member toward said valve seat, said housing having a second lateral aperture communicating the exterior of said housing at all times with and permitting flow of fluids at all times from the exterior of the housing into said passage of said elongate member, said second aperture having a smaller orifice than said first aperture, said fluid pressure responsive means comprising a bellows having one end connected to said elongate member and another end connected to said housing to form a chamber between said housing and said bellows, said passage of said elongate member and said second aperture opening into said closed space.

7. A well tool including: a housing having a flow passage and a lateral aperture intermediate the ends of said housing communicating said flow passage with the exterior of the housing; a valve means comprising an elongate body longitudinally slidable in said housing, said housing having a valve seat engageable by said elongate body when said elongate body is moved in one direction to one extreme longitudinal position; fluid pressure responsive means operatively associated with said elongate body for moving said elongate body from said one extreme position to an open position permitting fluid to flow between said aperture and said flow passage; and sealing means between said elongate body and said housing, said lateral aperture being disposed between said valve seat and said sealing means, said elongate body closing said flow passage to prevent flow of fluids from said aperture to said flow passage when said elongate body is in said one extreme longitudinal position, said elongate member having a flow passage communicating with said flow passage of the housing and extending past said sealing means to expose said fluid pressure responsive means at all times to fluid pressure from said flow passage of said housing, said housing having a second aperture intermediate the ends thereof communicating the exterior of said housing at all times with and permitting flow of fluids at all times from the exterior of the housing into said passage of said elongate member, said second aperture having a smaller orifice than said first aperture, said fluid pressure responsive means comprising a bellows having one end connected to said elongate member and another end connected to said housing to form a chamber between said housing and said bellows, said passage of said elongate member and said second aperture opening into said closed space; and cooperable stop means on said elongate member and said housing for limiting movement of said elongate member from said one extreme longitudinal position.

References Cited in the file of this patent UNITED STATES PATENTS 2,236,137 Grisham Mar. 25, 1941 2,620,741 Garrett Dec. 9, 1952 2,727,530 Grove Dec. 20, 1955 2,815,764 Bryan Dec. 10, 1957 2,982,226 Peters May 21, 1961 

1. A WELL TOOL FOR ADMITTING FLUIDS INTO THE INTERIOR OF A TUBING INCLUDING: A HOUSING CONNECTABLE TO THE TUBING AND HAVING A FLOW PASSAGE OPENING INTO THE INTERIOR OF A TUBING WHEN THE WELL TOOL IS CONNECTED THERETO, SAID HOUSING HAVING A LATERAL APERTURE COMMUNICATING SAID FLOW PASSAGE WITH THE EXTERIOR OF THE HOUSING AND OF A TUBING WHEN THE HOUSING IS CONNECTED THERETO; VALVE MEANS MOUNTED IN SAID HOUSING AND MOVABLE BETWEEN AN OPEN POSITION WHEREIN SAID VALVE MEANS PERMITS FLUIDS TO FLOW THROUGH SAID APERTURE AND THENCE INTO SAID PASSAGE AND A CLOSED POSITION WHEREIN SAID VALVE CLOSES SAID FLOW PASSAGE PREVENTING FLOW OF FLUIDS FROM SAID APERTURE AND THROUGH SAID FLOW PASSAGE; MEANS OPERATIVELY ASSOCIATED WITH SAID VALVE MEANS AND SAID HOUSING AND RESPONSIVE TO FLUID PRESSURE IN SAID FLOW PASSAGE FOR MOVING SAID VALVE MEANS FROM 